Implantable drug infusion systems are used to provide programmable long-term delivery of a therapeutic agent, e.g., infusate drug, to a target site such as the brain or the spinal canal or epidural space. These systems typically include a pump implanted at a remote location, e.g., within the abdominal or chest cavity, and a catheter tunneled from the pump to the target site. A drug may be delivered from a reservoir in the pump to the target site via the catheter.
Some therapies, e.g., treatment of many neurological diseases, may benefit from infusion of a therapeutic agent to multiple locations within the body. For instance, for the treatment of Parkinson's Disease, it may be beneficial to deliver a substance, e.g., Glial Derived Neurotrophic Factor (GDNF), to both hemispheres of the brain (bilaterally). Infusing a drug to such multiple target sites is typically accomplished by separate infusion systems, e.g., a separate pump and catheter system for each target site. However, duplicate systems result in not only increased costs and patient invasiveness (as compared to single target site systems), but also increased complexity that is inherent in such dual systems.
Branching catheter systems such as those described in, e.g., U.S. Patent Application Publication No. US 2004/0199128 A1 (Morris et al.) and titled CATHETER FOR TARGET SPECIFIC DRUG DELIVERY, have been developed to address some of the issues associated with using multiple systems for delivering drugs to multiple locations within a patient.